1. Field of the Invention
This invention relates to a photoelectric detecting device, and more particularly to a photoelectric detecting device in which a portion of a photoelectric detecting system for scanning a surface to be inspected by a light beam and for receiving the light from the inspected surface by a photoelectric detector, the photoelectric detection being effected in the view-field of the pupil, is common to a part of an observation optical system for illuminating the inspected surface with an illuminating light and observing the inspected surface.
2. Description of the Prior Art
A photoelectric detecting device in which a portion of a photoelectric detecting system for scanning a surface to be inspected by a light beam and for receiving the light from the inspected surface by a photoelectric detector is common to a part of an observation optical system for illuminating the inspected surface with an illuminating light and observing the inspected surface has already been proposed by our U.S. Application Ser. No. 870,081 now U.S. Pat. No. 4,165,149 filed on Jan. 17, 1978 (German Patent Application No. P 2802286.8 filed on Jan. 19, 1978). This invention relates to a improvements in such a device. The improvement resides in that photoelectric detection is effected without loss of light.